Coupling pin



July 13 1950 R. A.'w. sPooNER 2,515,807

couPLING PIN-V original Filed Jan. 5. 194s Patented July 18, 1950 UNITEDCOUPLING PIN Reginald Arthur William Spooner, Walton-on-Thames, EnglandOriginal application January 5, 1943, Serial No. 471,376, now Patent No.2,399,581, dated April 30, 1946. Divided and this application March 19,1946, kSerial No. 655,518. In Great Britain January 28, 1942 1 Claim.

This invention relates to coupling pins, such for example as pins usedfor coupling vehicles together.

This case is a division of application Serial No. 471,376, filed January5, 1943, which has now matured into Patent No. 2,399,531 of April 30,1946.

One object of the invention is to provide an improved means of locatingand retaining a v coupling pin in position axially.

Another object of the invention is to lock a coupling pin iirmly inposition while allowing it to be quickly released when desired.

A further object of the invention is to provide a coupling pin of whichthe part engaging the coupled members develops its full strength, andwhich will remain firmly locked in position but can easily be insertedand released.

In my present invention I make use of a principle of operation embodiedin the device described in my British Patent No. 524,297, that is tosay, I employ a tubular member containing one or more balls or theequivalent mounted to move in a radial bore or bores, and these ballsare caused to project out from the tubular member to form abutments bythe action of a springloaded member that is axially movable in thetubular member and that, on being moved against the spring, allows theballs to move inwards and cease to act as abutments.

The manner in which the objects of the present invention are attainedwill sbest be understood from the following description of an embodimentof it when taken in conjunction with the annexed drawing, which is avertical section through a vehicle coupling pin.

In the construction shown in the drawing, the pin consists of a longplain shank 3l with a head 24, and is shown in position in a towingvattachment for a vehicle. The shank enters openings in the arms 22a and22 of the forked end of one of the elements to be coupled and an eye inthe other member 32 which lies between the two forked arms. Adome-shaped member 23 is welded to the upper surface of the arm 22a soas to form above that surface a cavity 21 into which two balls 4 projectto lock the pin in position. These balls 4 can move in radial bores 3 inthe pin but are restrained from escaping outwards completely because themouths of the bores 3 are spun over. As before, the balls 4 are forcedto project outwards by a member 5 which can move axially in a bore 26 inthe head of the pin and which is formed with a waist 28. The upper partof the member |5 is surrounded 2 the mouth of the part I5 of the bore126. When axial pressure is applied to the cap I'I the member 5 movesdownwards to bring the waisted part 28 opposite the balls 4 so that thelatter can sink inwards in the radial bores 3. When they do this, thepin can easily be inserted and Withdrawn and when the cap II is releasedagain the spring I6 will restore the member 5 to its normal position,thus once more forcing the balls 4 outwards.

To facilitate operation a groove 2I is made around the head of the pinso that the operators fingers can engage in this while his thumb bearson the cap I 'I.

It will be seen that the arm 22a and domeshaped member 23 togetherconstitute an element with an internally recessed cylindrical openingthat is entered by the coupling pin.

It will also be seen that the whole of the retaining mechanism isaccommodated in the head of the pin and that the shank may be of anydesired length and is not weakened by an internal bore. The applicationof the dome-shaped member or its equivalent to the surface of thecoupled element is a very simple matter.

What I claim is! In combination, a coupling pin, a pair of elementscoupled by said pin, and a recessed element xed to a surface on one ofsaid elements and having an opening registering with the opening of saidelement entered by said pin, whereby a cavity is formed between saidsurface and said recessed element, said pin being formed in its headwith a bore and with at least one radial opening in the wall of saidbore, a member mounted to move radially in said bore to project from thesurface of said pin into said cavity, an operating member mounted tomove axially in said boreand shaped to force said radially movablemember to project outwards but on ibeing moved axially to allow saidradially movable member to sink inwards, and spring means for holdingsaid operating member in position to force said radially movable memberoutwards, the shank of said pin engaging said coupled elements beingformed with a-continuous cylindrical surface without openings.

REGDALD ARTHUR WILLIAM SPOONER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS iby a spring I6 mithin an enlarged part I5 `of 55Number Name Date the bore 26 and is secured by a screw I9 to a 854,073Bruckner et al. May 21, 1907 cap Il havinga skirt I8 formed with ashoulder 1,372,242 Mepsted Mar. 22, 1921 which engagesunder an internalflange 20 at 2,313,883 Lowther Mar. 16, 1943

